Mario Aguilar

Knight Capital lost $440 million in a flash on Wednesday when newly installed trading software went haywire. That's nearly double the company's second quarter revenue, and could be enough to sink Knight for good.

You know all the concerns about automated high-speed trading on the stock market? This.

The problem on Wednesday led the firm's computers to rapidly buy and sell millions of shares in over a hundred stocks for about 45 minutes after the markets opened. Those trades pushed the value of many stocks up, and the company's losses appear to have occurred when it had to sell the overvalued shares back into the market at a lower price.

Oopsies! What? How the hell does that happen by accident? This isn't the first time a computer error has caused massive losses on the stock market—in fact Knight took it on the chin during the NASDAQ Facebook IPO fiasco as well—and it's just going to keep happening if the industry isn't better regulated. Financial institutions hate regulation, but as this case plainly proves rules aren't just there to protect us plebs. They can save billionaire asses as well. [New York Times]